Tips To Make Sure Your Backyard Treehouse Is Safe

Updated: Jul. 27, 2023

Ready to build that backyard treehouse for your kids? Ensure it's safe by following these helpful tips from someone who built one for her kids.

A few years back, I built a backyard treehouse for my kids. It ended up being one of the most rewarding projects I’ve ever completed. Turns out, treehouses are more than just boards and screws in a tree — they’re magical places for children to play and pretend.

As a parent and professional handyperson, I set out to build a treehouse that was fun and safe, so I prioritized safety measures throughout the process. If you’re planning to build one for your kids, check out these tips to make sure yours is safe as well.

Choose the Location Wisely

Look for a tree or trees in a clear space on relatively flat ground. Avoid trees near:

  • Power lines;
  • Dead trees;
  • Large rocks;
  • Uneven ground.

All create potentially hazardous situations, so pick a site without any of these features.

Evaluate Your Trees

Choose a hardwood tree like maple, oak or hickory for your base. These hold anchors well and are stronger than softwood trees like pines, which should be avoided.

Make certain it’s a healthy, mature tree, with no visible signs of disease or rot. If you’re unsure, hire an arborist. Remove any dead branches overhead in your chosen tree or ones nearby.

Design with Safety in Mind

A lot of factors go into planning a treehouse. One of the most important: The distance between the treehouse and the ground, because falls pose the highest risk of injury.

Four to six feet is a typical treehouse height, but certainly no more than 10 feet. The shorter the distance to the ground, the safer the treehouse.

To prevent bruised foreheads, plan to accommodate your child’s current and future size. This will determine overall dimensions, as well as doorway and ceiling height. Remember: Children grow quickly.

Other design features that promote safety include:

  • Sloped roof: This quickly sheds water and snow, keeping your treehouse rot-resistant and sturdy for years.

  • Sturdy floor platform: Study local deck building codes to determine the safest lumber thickness, railing height, hardware and joist spacing to incorporate into your design. Codes can usually be found on local building department or zoning board websites. If not, contact your town or municipal office for a copy.

  • Walls instead of railings: Railings may save time and materials, but walls prevent falls better and should always be part of a treehouse design. Walls framed with 2x4s and finished with an exterior sheathing like T-111 siding will easily withstand weather and keep everyone safe.

  • Safety railings: Use on decks, ladder landings or any open floor section not enclosed by walls.

  • Adequate anchor system: This is the foundation of any safe backyard treehouse design. Treehouse attachment bolts and 2×12 lumber directly bolted to the tree are two common systems.

  • Ladders: Wood ladders offer the safest means of entering and exiting the treehouse and contribute to overall safety.

Use Quality Materials

Choose exterior-grade materials like cedar or pressure-treated wood that are rot-resistant and tolerate extreme weather conditions. Use quality construction screws meant for exterior and structural applications.

If using pressure-treated wood, go with all galvanized fasteners to prevent corrosion. Avoid repurposed or recycled wood for the safest results.

Select the Right Anchor System

Treehouse attachment bolts (TABs) are the industry-preferred method to secure treehouses to trees. These thick steel bolts come with a wide collar and screw into trees.

Unlike a lag bolt, TABs feature several inches beyond the collar that remain outside the tree. Structural lumber rests on this extension, secured with a specially-designed clamp. This method doesn’t harm the tree, allows for tree growth and movement and withstands thousands of pounds of weight.

Other anchoring options may hurt the tree, inhibit growth or trap water between the tree and support boards, leading to decay.

Build Safe Entries and Exits

Build sturdy, permanent ladders with 2x4s for visitors to safely enter and exit the treehouse. Make sure to account for a landing space at the top of the ladder. Avoid ropes and rope ladders, which break down quickly in weather and pose strangulation risks.

Secure Guardrails and Railings

Railings should be at least 36 inches high with balusters spaced no more than four inches apart. Attach railings to properly secured 4×4 posts. Attaching posts to skirt boards with through-bolts and nuts is a common deck-building practice; check local codes for additional information.

Use vertical balusters rather than horizontal ones, which encourage climbing and possible falls. If your plan allows, install handrails along ladders for additional safety.

Perform Regular Maintenance and Inspection

Regularly inspect your backyard treehouse for rotted wood and loose screws, and make any necessary repairs. Inspect TABs each year and tighten clamps as needed. Ensure the tree is still healthy and hasn’t become diseased or stressed by the treehouse.

Sand down any raised wood grain to avoid splinters. Treated lumber will dry and shrink, becoming loose, cracked or broken. Look for any signs of this and repair or replace.

Add Safety on the Ground

Consider putting wood chips or rubber playground mulch under and around the treehouse to cushion any accidental falls and prevent serious injuries.